1. The Field of the Invention
The present invention relates to an electrochemical water purifier. More particularly, the invention relates to a method and apparatus for the purification of impure water using a conjugated system of electrolytic currents and electrostatic fields.
2. The State of the Art
This invention relates, in general, to a method and apparatus for electrochemically altering contaminants found in aqueous solutions, so as to facilitate their simplified extraction, and thereby provide purified potable water.
The chemical compound H2O is a very unusual substance with many unique properties that contribute to its life supporting role in nature. Like the air we breathe, water is central to life, and is required in relatively large quantities. Nothing is more familiar to each of us, and yet, most people living in developed countries usually take water and its quality for granted. Generally speaking, unless there is an emergency or shortage wrought by drought or contamination, most people seldom think about where it comes from, what it contains, how pure it is, or how long our supply of it will last. We simply turn on a faucet, and expect a sufficient quantity of clean pure water to come flowing out.
To put things in better perspective, of the total water found on earth, very little is found in a pure enough condition to even be considered as a source for drinking purposes. Our oceans contain 97.4% of all of the water found on earth. Fresh water sources are limited to the polar ice caps, glaciers, above ground bodies of water, and underground aquifers, which together contain only 2.59%. Surprisingly, all of our lakes, rivers, streams, soil, and atmosphere combined only contain a mere 0.014%!
Until a decade or two ago, the term “Bottled Water” was practically unheard. Today, however, as people become more aware of the harmful substances that may be found in municipal or private water supplies, bottled water is big business with annual revenues in the United States towering over four billion dollars. Presently, more than three billion gallons of bottled water are sold each year in the United States and in Europe. Bottled water is now the largest selling “soft drink” in these regions. However, bottled water is very expensive relative to tap water, typically, selling anywhere from $0.50 to $1.00 a quart. This is thousands of times more expensive than tap water. Concern for personal safety, and the possible long term health risks associated with drinking contaminated or polluted water, continues to drive this market in spite of the high cost.
All groundwater, including that fit for drinking, contains dissolved chemical substances. The exact composition of groundwater depends on the original composition of the precipitation before it enters the ground, the nature of the soil that first makes contact with the precipitation, the minerals that make up the rocks in the saturated zone, the Water temperature, and the presence of industrial or other human contaminants. Total dissolved substances in groundwater range from about 20 to more than 300,000 milligrams per liter.
Almost all human activity alters water quality somewhat, but not necessarily as a result of pollution by human materials. For instance, in some areas, reduction of water levels in the subsurface by pumping may allow saline water to flow toward the wells; this occurs most often in coastal areas. Domestic waste (sewage and solid trash), however, is the most serious source of groundwater contamination. Solid trash, if accumulated in large amounts in humid regions, can become a major source of concentrated pollution. Water moving through the decaying trash can dissolve thousands of milligrams per liter of noxious material, including poisonous metals and flammable methane.
Human activity has increasingly polluted our precious sources of fresh water. Today, many of our long held and heavily relied on sources of fresh water have become so polluted that they can no longer be used without considerable health risks or concern. Even though some of the contamination is a result of naturally occurring events, human beings are still the primary perpetrators. For example, pollution from factories, heavy mining operations, industrialized farming practices, concentrated animal rearing and feeding operations, as well as misuse of solvents and other chemically formulated “fix all” products have contaminated the air we breathe and the water we drink. Pollutants include such things as cadmium, chromium, lead, mercury, radionuclides, arsenic, nitrates, phosphates, benzene, trihalomethanes, methyl tertiary butyl ether (MTBE), pathogenic microorganisms, insecticides, and herbicides to name just a few.
Addressing water pollution has become a formidable challenge, and water pollution presents a continued health risk to people all over the earth. Thousands of people each year are being poisoned as a result of drinking contaminated water. Consequently, keeping public water supplies safe has long been recognized as an important public health issue by all developed countries.
In 1974, the U.S. Congress passed the Safe Drinking Water Act (SDWA) in response to public concern about findings of harmful substances in drinking water supplies. Contaminants that may pose health risks are regulated by the EPA, as required by the SDWA, as amended in 1996. For example, the EPA recently lowered its standard for arsenic from 50 μg/L to 10 μg/L. Higher concentrations have proven to have a profound effect on the risk of developing cancer. There are now more than 80 EPA regulated contaminants for water quality. Prudence dictates that we continue to take all of the necessary steps to protect the earth's life sustaining waters from contamination, and provide a means whereby people throughout the world may have access to an abundance of clean, pure, economically derived water.
In addition to removing pollutants, an important consideration regarding the art of purifying contaminated water is that of removing excessive amounts of calcium, magnesium, and iron as these minerals can lead to a condition known as hardness. Hard water interferes with almost every cleaning task from laundering and dishwashing to bathing and personal grooming. Clothes laundered in hard water often look dingy and feel harsh and scratchy. Dishes and glasses may be spotted when dry. Hard water may cause a film on glass shower doors, shower walls, bathtubs, sinks, faucets, windows etc. Hair washed in hard water may feel sticky and look dull. Hard water deposits in pipes may also reduce water flow.
The amount of hard minerals in water affects the amount of soap and detergent necessary for cleaning. Soap used in hard water combines with the minerals in water to form a sticky soap curd. Some synthetic detergents are less effective in hard water because the active ingredients are partially inactivated by hardness, even though they remain dissolved. Bathing with soap in hard water leaves a film of sticky soap curd on the skin. The film may prevent removal of soil and bacteria. Soap curd interferes with the return of skin to its normal, slightly acidic condition, and may lead to irritation. Soap curd on hair may make it dull, lifeless and difficult to manage. When doing laundry in hard water, soap curds lodge in fabric during washing to make the fabric stiff and rough. In addition, concentrations of iron in the water greater than 0.3 mg/L can also cause staining of laundered clothes, dishes etc. Incomplete soil removal from laundry causes graying of white fabric and the loss of brightness in colors. A sour odor can also develop in clothes due to incomplete removal of contaminants. Continuous laundering in hard water can shorten the life of clothes.
Hard water also contributes to inefficient and costly operation of water using appliances. Heated hard water forms a scale of calcium and magnesium minerals that can contribute to the inefficient operation or failure of water using appliances. Pipes can become clogged with scale that reduces water flow and ultimately requires replacement. Hard water and the subsequent requirement of additional body, laundry and dish soaps, the use of chemical additives and softening agents also adds to the increased treatment and eventual pollution of our underground aquifers and fresh water sources.
Present water purifying and conditioning systems, however, are very lacking in their ability to effectively and efficiently remedy many of the afore mentioned contaminations. Distillation, for example, is simply too costly to even be considered as a mainstay solution.
Reverse osmosis systems not only waste a lot of water in the process of keeping the RO membrane clean and operable, but changes in water temperature passing through the membrane influences the membrane's ability to filter out certain, unwanted, contaminants such as arsenic. The RO process is also expensive to operate and maintain due to the high pressure required for its operation, and the frequently required replacement of costly filters and membranes
Ozonation is effective in the removal of some of the heavy metals, as well as fractions that are of organic origin, but it is also very expensive to operate, and it will not remove many of the hazardous contaminants mentioned earlier such as arsenic and phosphorous.
Granulated, activated charcoal (GAC) systems will only remove narrow portions of the typical aqueous contaminations such as certain odor causing fractions, fractions of organic origin, and some of the chlorine and chemical contaminants. However, its removal efficiency rapidly diminishes over time requiring frequent replacement, and it will not remove many of the toxic or hazardous contaminants.
Ion exchange resin systems remove only a fraction of the contaminants mentioned above. They are used primarily to “soften” the water by removing calcium and magnesium ions, which pose absolutely no health risks, in exchange for sodium at the rate of about 8 mg/liter for each grain of hardness removed per gallon of water. Scientific research has shown that water treated in this fashion releases enough sodium to aggravate, or lead to, cardiovascular disorders. The state of California recently passed legislation outlawing any new installations of such due to the high levels of salt discharge into the sewerage systems which are required to regenerate their effectiveness. Furthermore, the removal of many contaminants, such as iron, via ion exchange technology requires the use of very harsh chemicals such as potassium permanganate in order to regenerate. Such chemicals only exacerbate the escalating problem of ground water contamination, as they may be discharged, unaffected, from present art wastewater treatment facilities.
Electro coagulation systems are somewhat effective in the removal of many of the EPA regulated contaminants; however, they do not meet all of the necessary drinking water standards. Moreover, electro coagulation systems do not provide a means to electrochemically recover virtually all of the excess anodally liberated ions, metallic oxides or colloids. Failure to remove these adscititious elements may introduce serious environmental concerns and health hazards. For example, high concentrations of aluminum in aqueous solutions will kill or injure a wide variety of plant and animal life, including fish. Consequently, all prior art systems require additional filtration through zeolites and/or secondary ion exchange systems to achieve potability. These ancillary filtration devices must be either replaced or regenerated using chemical additives so the use of such may be considered irresponsible.
Some prior art devices claim pathogenic reductions following the treatment of contaminated sources, but the mechanisms employed to accomplish this objective, namely, fragmentary ozonation at the anode surface as stated in U.S. Pat. No. 4,872,959, direct electric current as in U.S. Pat. No. 5,091,152, or areas of high temperature as in U.S. Pat. No. 5,271,814, do not comprise an efficient, universal, or a certifiably complete means to achieve axenic sterilization.
Moreover, as in U.S. Pat. Nos. 4,293,400, 4,378,276 and 4,872,959, integral obstructions fixed between an anode/cathode pair, such as a helical wrap, may be somewhat effective as a spacing member, or even as a means to manipulate the retention time of the solution being treated. However, because a significant percentage of the effective surface area of both the anode and cathode is occluded, an electrolytic cell of this design must be increased in length proportionate to the total square area of the obstruction in order to retain relative efficiencies resulting in higher manufacturing costs and maintenance expenses. This problem is exacerbated anytime the effective surface area of an anode/cathode pair is rendered inefficacious by use of an anode having a greater effective surface area than its corresponding cathode, as in U.S. Pat. Nos. 4,293,400, 4,378,276 and 4,872,959, or whenever abrupt, non uniform, current densities exist along any electrode surface as in U.S. Pat. Nos. 5,043,050, 5,271,814, and 5,423,962.
Furthermore, the absolute majority of electrolytic prior art systems and technologies emphasize a means for routinely operating a described apparatus in a reverse polarized condition to facilitate a cleansing of the anode/cathode surfaces employed. While there are some short term benefits derived from this technique, reversing polarity over extended periods of time will eventually pacify both electrodes, rendering them non conductive and ineffective. Additional complications arise if the anode and cathode of an electrolytic device are composed of dissimilar materials. By way of example, U.S. Pat. No. 4,872,959 describes an apparatus, which principally utilizes iron and aluminum as anodes and cathodes. Therefore, while operating this device in one direction of polarity, high concentrations of ionic or colloidal aluminum will be discharged with the treated solution, and while operating in a reverse polarized condition the adscititious contaminant will be high concentrations of ionic or colloidal iron. The oscillating nature of the excess anodally liberated metal oxides introduced by such prior art electrolytic devices pose complicated environmental and human health considerations.
No prior art electro coagulation system or technology is capable of electrochemically extracting both non electrolytes and electrolytes from solution. Non electrolytes are, by definition, non ionic, non conductive compounds that remain unaffected by electrolytic influences and/or processes. These contaminating fractions can only be electrochemically influenced following adequate exposure to high voltage, ionizing, electrostatic fields of sufficient intensity to transform these compounds into ionic, conductive, species that may then be extracted from solution by means of precipitating electrochemical reactions, or via electrostatic filtration systems or technologies. Although some prior art systems and technologies utilize electrostatic fields, while others employ electrolytic currents, no prior art system or technology provides a means for the incorporation of both of these complementary electromotive forces within a conjugated treatment cell. Consequently, these apparatus may remove only a portion of the full spectrum of contaminants.
With the foregoing background of the invention in mind, and as the following description of the invention proceeds, it is desirable to provide an improved system for the concerted electrostatic and electrolytic, and/or uncompounded electrolytic, treatment of aqueous solutions which is free of the aforementioned and other such disadvantages of the prior art configurations. The system should provide clean, safe, softened, pathogen free, inexpensive, pH balanced, potable water without the use or necessity of secondary purification systems or technologies such as absorption filters, ion exchange systems, or zeolites, etc. It should be understood, however, that conjunctive use of such secondary filtration technologies might not in every instance be proscribed and is within the scope of the present invention.
It is further desirable to provide an improved system for the efficient and effective extraction, or safe level reduction, of all EPA regulated or non regulated, metal or non metal, contaminants encountered within aqueous fractions with very few possible exceptions by means of concerted electrostatic ionic separations and precipitating electrochemical reactions, and/or fundamental precipitating electrochemical reactions, without the use of salt brine solutions or the addition of harsh chemicals.
It is yet further desirable to provide an improved system for the efficient and effective softening of aqueous solutions by means of concerted electrostatic ionic separations and precipitating electrochemical reactions, and/or fundamental precipitating electrochemical reactions, without the use of salt brine solutions or the addition of harsh chemicals.
It is yet further desirable to provide an improved system for the efficient and effective extraction of virtually all autochthonous contaminants, as well as excess anodally liberated adscititious metal ions. These may be either electroplated or precipitated out of solution by means of sequentially complementary anode/cathode pairs (treatment cells) having maximized efficiencies, efficacies, concentrically uniform field/current densities, particularized redox potentials, and specific solution pH altering capacities, inherent in the structure and composition of the invention.
It is yet further desirable to provide an improved system for the efficient and effective maximization of solution retentivity and homogeneity. Optimally, aqueous solutions traversing a treatment cell shall be constrained to move as an upward vortical flow by means of one or more low profile, disk shaped, non conductive, electrode spacing members further engineered to induce a directionally specific vortical acceleration upon fractions passing through its plurality of equidistant, homocentrically arrayed, and biased orifices.
It is yet further desirable to provide an improved system for the efficient and effective maximization of solution retentivity and homogeneity, wherein, electrode surfaces shall be smooth, or gently undulated and helically oriented, so as to respectively facilitate an unimpeded or augmented vortical flow within a treatment cell; thereby, rectifying undesirable upward convective currents induced upon the solution by electrode off gassing.
It is yet further desirable to provide an improved system for the efficient and effective maximization of anode/cathode efficiency and efficacy by using treatment cells which are unimpeded by lengthy integral obstructions fixed between an anode/cathode pair, such as a helical wrap. The use of relatively unobstructed anode/cathode pairs facilitates net reductions in cell length and diameter as well as inherent reductions in manufacturing and maintenance expenses.
It is yet further desirable to provide an improved system for the efficient and effective maximization of anode/cathode efficiency and efficacy, wherein, the effective surface area of any given cathode shall be greater than or equal to the effective surface area of its corresponding anode. Having a cathode with greater surface area than the corresponding anode helps offset any pacification resulting from accumulating non conductive gasses and/or oxides on either electrode surface as well as changes in electrode diameter due to sacrificial consumption, or enlargement due to electroplating.
It is yet further desirable to provide an improved system for the efficient and effective maximization of anode/cathode efficiency and efficacy, wherein, electrolytic and concerted electrostatic current/field densities are made concentrically uniform. This has been determined to be an exceedingly important factor during the purification process as well as increasing longevity, and maintaining continued successful operation.
It is yet further desirable to provide an improved system for the efficient, effective, and universal sterilization of pathogenic microorganisms by means of synergistic anode/cathode (treatment cell) arrangements, embedded within a treatment cell array, and which possess inherent germicidal properties such as with a copper/aluminum anode/cathode pair.
It is yet further desirable to provide an improved system for offsetting the operational cost of the apparatus by providing a means to efficiently and effectively claim, and/or recycle, all such elements as may have electroplated out of solution on cathode surfaces.
It is yet further desirable to provide an improved system for offsetting the operational cost of the apparatus by providing a means to harvest the chemically diverse precipitates, and/or soluble ionic compounds.
It is yet further desirable to provide an improved system for offsetting the operational cost of the apparatus by providing a means to efficiently and effectively collect, purify, and store the hydrogen gas which is liberated during treatment and which may then be used as a recoverable source of energy. For example, purified hydrogen could be ported from a storage system or technology to a fuel cell, combustion generator, etc., where it would be spent to produce electric power. This reclaimed energy could then be subsequently cached in a battery, super capacitor, etc., or immediately applied to subsidize the operational energy requirements of the present invention, or for use in other devices or purposes. Alternatively, the purified hydrogen gas could be harvested for later use.
It is yet further desirable to yield a variety of embodiments, adaptable and suited to the constituents of the aqueous solution to be purified, so as to accommodate a diversity of two or more sequentially complementary anode/cathode pairs (forming a treatment array), and which are comprised of any combination or species of conductive, efficacious, metal and/or non metal material.
It is yet further desirable to accommodate the automatic application of DC bias voltages sufficient to neutralize the redox potentials of any given anode/cathode pair comprising a natural electrolytic cell, of either direction, after operating voltages are disengaged. These retaining voltages shall, accordingly, be discontinued when normal operation of the apparatus resumes.
It is yet further desirable to facilitate a means for periodic, short term, reverse polarization of electrodes which may be at times requisite to revitalize the efficiency and efficacy of certain anode/cathode pairs that may be employed within an array.
It is yet further desirable to accommodate the automatic evacuation of the aqueous solution contained within predetermined treatment cells to a sewer or wastewater treatment system after operating voltages are disengaged.
It is yet further desirable to accommodate the automatic evacuation of the solution contained within predetermined treatment cells to a sewer or wastewater treatment system following a reverse polarization of electrodes which may be periodically requisite to revitalize the efficiency and efficacy of certain anode/cathode pairs that may be employed within an array. It should also be noted that normal operation of the apparatus during such a cleaning cycle may be electively suspended. It will be further appreciated, however, that implementation of these procedures shall not be required in all cases, and should be employed sparingly.
It is yet further desirable to provide a means whereby the aforesaid evacuated solution may be electively replaced with CO2, or any other efficacious, non hazardous, environmentally safe compound, which may serve to prevent or remove non conductive film accumulation upon electrode surfaces. Aforesaid revitalizing compounds would, in turn, be harmlessly discharged to a sewer, wastewater treatment system, or holding tank before normal operation of the apparatus resumed.
It is yet further desirable to yield a variety of embodiments, adaptable and suited to the constituents of the aqueous solution to be purified, so as to accommodate the conjunctive use of pH altering systems and technologies, preceding and/or following the usage of any given treatment cell, including, but not limited to, CO2 infusion systems designed to produce carbonic acid, subsequently lower the pH of the processed solution, and further induce some dissolved contaminants to form precipitates that may then be easily extracted.
It is yet further desirable to yield a variety of embodiments, adaptable and suited to the constituents of the aqueous solution to be purified, so as to accommodate individual treatment cells, within the array, being energized by either concerted high voltage DC electrostatic fields and low voltage DC electrolytic currents, or uncompounded DC electrolytic currents, in order to efficiently and effectively extract non electrolytic, electrolytic, and colloidal contaminants from solution by means of specifically tailored electrochemical reactions.
It is yet further desirable to yield a variety of embodiments, adaptable and suited to the constituents of the aqueous solution to be purified, so as to facilitate an assortment of collection points, or means, in order to efficiently and effectively harvest the chemically diverse precipitates, and/or soluble ionic species such as nitrates, nitrites, salts, etc.
It is yet further desirable to provide a filtration system with a relatively long life span.
It is yet further desirable to consume a minimal amount of energy while operating the invention described herein.
It is, yet further desirable to provide filtration system which may be constructed in a variety of sizes that may satisfy the need of a single individual, a small home or dwelling, or a large scale municipal water treatment facility.
It is yet further desirable to provide a variety of embodiments, adaptable and suited to the volumetric amount of aqueous solution to be treated, so as to efficiently and effectively dispense purified water by means of a reservoir tank, a pressure tank, or on demand, etc., as circumstance may prescribe.
It is yet further desirable to provide a relatively compact sized water treatment system. The water treatment system is thus more useful as it may be used in residential and smaller commercial applications.
It is yet further desirable to facilitate the optional use of automatic controls to reduce the necessity of human intercession in the operation of the invention.
It is yet further desirable to provide a filtration system which has reduced maintenance requirements, operational expenses, and manufacturing costs. The filtration is thus less expensive to purchase and operate, making the filtration system more available to individuals in need of such a filtration system.